• Preventive Nutrition and Food Science
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• 제2권2호
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• pp.89-95
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• 1997

The comparative effects of gamma irradiation an ozone treatment on the microbiological and physicochemical qualities were investigated for the improvement of hygienic quality of aloe powder and bee pollen. Gamma irradiation at 7.5~10kGy could reduce total aerobic bacteria, molds and coliforms below detection levels, but ozone treatment up to 18 ppm for 8hr was not sufficient to eliminate the microorganisms from aloe powder and bee pollen. The physicochemical properties such as fatty acid an amino acid compositions, mineral content, TBA value, barbaloin and pigment contents were not significantly changed by gamma irradiation, whereas ozone treatment caused significant changes in fatty acid composition, lipid oxidation and destruction of barbaloin and natural pigments.

• PNF and Movement
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• 제19권1호
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• pp.97-104
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• 2021

Purpose: The human body can experience a variety of injuries. As a result, it may be difficult to directly treat the damaged area. In such a case, indirect treatment is required. Indirect treatment is typically PNF treatment. Morphological changes in muscle have been confirmed through several previous studies; however, few studies have analyzed neurological changes. Therefore, the purpose of this study was to determine how irradiation during resistance exercise using a diagonal pattern effects neurological excitability. Methods: Electromyography was performed on 13 healthy adults. A compound muscle action potential (CMAP) was obtained through a median motor nerve conduction velocity test, which was conducted before and after performing the irradiation exercise and general exercise. Results: Compared to baseline measurements, there was no significant difference in the latency of the irradiation exercise and general exercise. The amplitude of the CMAP measured after the irradiation exercise was significantly higher than after general exercise. Conclusion: Neurological excitability was high in irradiation during resistance exercise using a diagonal pattern. When clinically direct treatment is difficult, it is thought that irradiation can be used indirectly as a technique to induce nerve excitability.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2408-2417
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• 2022

The nanoindentation behavior of P92 steel with thermomechanical treatment under 3.5 MeV Fe¹³⁺ ion irradiation at room temperature, 400 and 700 ℃ was investigated. Pop-in behavior is observed for all the samples with and without irradiation at room temperature, while the temperature dependence of pop-in behavior is only observed in irradiated samples. The average load and penetration depth at the onset of pop-in increase as the irradiation temperature increases, in line with the results of the maximum shear stress. Irradiation induced hardening is exhibited for all irradiated samples, but there is a significant reduction in the hardness of sample irradiated at 700 ℃ in comparison to the samples irradiated at room temperature and 400 ℃. The ratio of hardness to elastic modulus for all samples decreases with increasing penetration depth except for samples at 700 ℃. With the increasing of irradiation temperature, the ratio of the irreversible work to the total work gradually decreases. In contrast, it increases for samples without irradiation.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4084-4094
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• 2022

The Advanced Fuels Campaign Fission Accelerated Steady-state Test (FAST) at Idaho National Laboratory (INL) completed its first irradiation cycle within the Advanced Test Reactor (ATR). The test focused on the irradiation of alloy fuel forms for use in sodium fast reactors. The first cycle of FAST testing was completed and four rodlets were removed for the initial post irradiation examination (PIE). The rodlet design and irradiation conditions were evaluated using Monte Carlo N-Particle (MCNP) for as-run power history and COMSOL for temperature analysis. These rodlets include a set of low burnups (~2.5 % fissions per initial metal atoms [%FIMA]), control rodlets, and a helium-bonded annular rodlet (4.7 %FIMA). Nondestructive PIE has been completed and includes visual inspection, neutron radiography and gamma scanning of the FAST capsules and rodlets. Radiography confirmed the integrity of the experiments, revealed that the annulus in the annular fuel was filled at a modest burnup (4.7 %FIMA), and indicated potential slumping of the cooler rodlets at lower burnup. Precision gamma scanning indicated mostly usual fission product behavior, except for cesium in the He-bonded annular fuel. Future destructive PIE will be necessary to fully interpret the effects of accelerated irradiation on U-Zr metallic fuel behavior.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.114-122
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• 2024

Irradiation-induced defects and the precipitates in the wrapper material of the Indian Fast Breeder Test Reactor (FBTR), SS 316 are analyzed using the synchrotron source-based Angle Dispersive X-Ray Diffraction (ADXRD) technique with X-rays of energy 17.185 keV (wavelength ~0.72146 Å). The differences and similarities in the high displacement damage samples as a function of dpa (displacement per atom) and dpa rate in the range of 2.9 × 10^-7- 9 × 10^-7 dpa/s are studied. Ferrite and M₂₃C₆ are commonly observed in the present set of high displacement damage 40-74 dpa SS 316 samples irradiated at temperatures in the range of 400-483 ℃. Also, the dislocation density has increased as a function of the irradiation dose. The X-ray diffraction peak profile parameters quantified such as peak shift and asymmetry show that the irradiation-induced defects are sensitive to the dpa rate-irradiation temperature combinations. The increase in yield strength as a function of displacement damage is also correlated to the dislocation density.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.262-268
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• 1996

In Korea, the health authorities and food industry emphasize the need of sanitary food production, which in mainly resulted from the recent growing of consumer's interest in the safety of food. For the reason, development of a new alternative technology to chemicals, currently used for decontamination and disinfestation, has become and urgent task in the domestic and worldwide food industry. Furthermore, the improvement of quality and manufacturing process of processed food is a requisite for winning the competition in export fields. Irradiation technology being practically applicable in the food industry has been well established on the basis of more than 40 years of R&D work in the fields of the increasing availability of food-stuffs, sanitary food production and quarantine treatment in the food trade. The wholesomeness of irradiation foods has been officially approved in 38 countries, of which 30 countries are commercially utilizing food irradiation technology. The first commercial irradiator in Korea(18.5PBq:500k{TEX}$Ci^{60}${/TEX} Co, max. cap; 4MCi) was established at Yeoju-gur, Kyung Ki-do with the technical assistance of Korea Atomic Energy Research Institute in June 1987. As of 1996, thirteen irradiated food groups (over 25 items)have been domestically approved for human consumption and an industrial irradiation facility is also available. However, the domestically approved for human consumption and an industrial irradiation facility is also available. However, the promotion of consumer acceptance to toward ir-radiated foods is considered as a confronted subject to be studied for a commercial utilization.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.715-724
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• 1996

This study was performed to identify the proliferation and to measure the alteration of alkaline phosphatase activity in human gingival fibroblasts cultured. For the present study, the authors cultured the human gingival fibroblasts oriented from the sound interdental gingiva, and used third passage. It was used methyl $[^3H]$ Thymidine to identify the proliferation in human gingival fibroblasts and used 410nm of the spectrophotometer to measure the alteration of the alkaline phosphatase activity in human gingival fibroblasts. The results were as follows: 1. There was a statistically significant increase in the proliferation of gingival fibroblasts following low level laser irradiation at 24 hour(p<0.05). 2. There was a statistically significant increase in activity of alkaline phosphatase compared to control group at 5-day laser irradiation after in laser irradiation groups(p<0.05). And there was a statistically significant increase in activity of alkaline phosphatase compared to control group at 7-day laser irradiation after in the I-minute laser irradiation group(p<0.05), but there was a statistically significant decrease in activity of alkaline phosphatase compared to 1minute laser irradiation group at 7-day laser irradiation in the 2-minute laser irradiation group after(p<0.05). The results, within the limits of the present experiments, suggest that, the low level laser irradiation accelerates the proliferation of gingival fibroblasts and alters the alkaline phosphatase activity until the restricted period.

• Journal of Animal Science and Technology
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• 제51권1호
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• pp.75-80
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• 2009

Composition changes of swine manure and the effects on MAP ($MgNH_4PO_46H_2O$) crystallization by microwave irradiation were examined. The concentration of ${PO_4}^{3-}$ was increased within a fixed period of time and then decreased, but $NH_4$-N was reduced continuously during microwave irradiation. Concentration of ${PO_4}^{3-}$ was started to reduce just from the point of foam formation during microwave irradiation, and the temperature at that time was always $49^{\circ}C$ irrespectively to microwave irradiation rate. Inorganic carbon was reduced with microwave irradiation, but soluble organic carbon (TOCs) was increased proportionally. Crystallization rate under conditions of non-microwave irradiation, irradiation up to $93^{\circ}C$ and $48^{\circ}C$ was 87.8%, 87.3% and 98.5%, respectively, showing 10% enhancement when irradiated up to $48^{\circ}C$. However, removal efficiency of ammonia nitrogen was proportional to the microwave irradiation rate or duration, obtaining 2.5%, 4.5% and 10.2%, respectively. Based on these results, it would be a useful strategy to irradiate microwave up to $49^{\circ}C$ to enhance MAP crystallization rate by changing the ionic pattern of nutrients in the manure. Meanwhile, provision of enough microwave irradiation rate might be needed to achieve high $NH_4$-N removal.

• 환경위생공학
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• 제22권4호
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• pp.11-21
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• 2007

The recent investigation indicates that the kinetic constants for anionic ions were merely the result of ion exchange between the algae cell wall surface and the anionic ion. In this study, Zygnema sterile and Lepocinclism textra, floating flagellate alga as the dominant algae strains, were cultivated using HRABR(High Rate Algae Biomass Reactor) and the cultivation conditions were 24 hrs. and 12 hrs. irradiation and it was studied how this algal biomass acts on the biosorption mechanism of anionic N and P. Results are as follows : 1. Calculating the specific chl.-a growth rate using Michaelis-Menten model, the one of 24hrs. irradiation was about 55 times higher than the one of 12 hrs. irradiation 2. Calculating the specific chl.-a growth rate using Kuo model, the one of 24 hrs. irradiation was about 2.26 times higher than the one of 12 hrs. irradiation 3. Langmuir model can apply to the biosorption mechanism of anionic N and P in HRABP. 4. Regarding the chlorophyll-a concentration as unit weight of sorbent, the ion selectivity coefficients for N and P are as follows : $(NH_3-N)+(NO_3-N)$ in 24 hrs. irradiation ; 44.984 $PO_4-P$ in 24 hrs. irradiation ; 24.237 $(NH_3-N)+(NO_3-N)$ in 12 hrs. irradiation ; 1432.851 $PO_4-P$ in 12 hrs. irradiation ; 599.076

• 환경생물
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• 제21권4호
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• pp.400-404
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• 2003

This study was to evaluate the effects of gamma irradiation on the germination, nutrient concentrations and growth of spinach and radish. Both the spinach and radish seeds exhibited relatively higher germination rates in response to the low doses of gamma irradiation compared to the non -irradiated control. Leaf DW of the radish did not respond to gamma irradiation but that of the spinach increased significantly in response to a gamma radiation of 4 Gy (P< 0.05). Leaf growth parameters of the spinach including the leaf area and SLA (leaf area/leaf dry weight) also demonstrated increased responses to gamma irradiation. R/S (root dry weight/shoot dry weight), root DW and root length of the spinach exhibited a positive response to gamma irradiation while those of the radish did not. In contrast, SRL (root length/root dry weight) significantly decreased with gamma irradiation at 8 Gy for the spinach, but not for the radish. The tissue nitrogen concentrations of the spinach showed an increased response to gamma irradiation while that of the radish did not. Furthermore, higher concentrations of phosphorus, potassium, calcium and magnesium were found in the irradiated spinach, but not in the irradiated radish. It seems that the non-specific physiological and/or biochemical activities of spinach might be accelerated by gamma irradiation, possibly accounting for the stimulation of nutrient uptake from the root media and early biomass accumulation in the current study.